78967 If the product of the matrix \(B=\)
\(\left[\begin{array}{ccc}2 & 6 & 4 \\ 1 & 0 & 1 \\ -1 & 1 & -1\end{array}\right]\) with a matrix \(A\) has the inverse
\(C=\left[\begin{array}{ccc}-1 & 0 & 1 \\ 1 & 1 & 3 \\ 2 & 0 & 2\end{array}\right]\), then \(A^{-1}\) equals

78968 If \(A=\left[\begin{array}{ll}2 & -3 \\ 5 & -7\end{array}\right]\), then \(A+A^{-1}=\)

78969 If \(A^{2}-A+I=0\), then the inverse of \(A\) is

78970 If \(A=\left[\begin{array}{ccc}2 & 3 & -5 \\ 1 & 4 & 9 \\ 0 & 7 & -2\end{array}\right]\), then apply \(C_{3} \rightarrow C_{3}+3 C_{2}\) to form a matrix \(B=\left[b_{i j}\right]\) and then find the value of \(a_{22}+b_{21}\) and \(a_{11} b_{11}+a_{22} b_{22}\) respectively.

78971 If \(\mathbf{A}=\left[\begin{array}{ccc}\sec \theta & \tan \theta & \mathbf{0} \\ \boldsymbol{\operatorname { t a n }} \theta & \boldsymbol{\operatorname { s e c }} \theta & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{1}\end{array}\right]\), then

78967 If the product of the matrix \(B=\)
\(\left[\begin{array}{ccc}2 & 6 & 4 \\ 1 & 0 & 1 \\ -1 & 1 & -1\end{array}\right]\) with a matrix \(A\) has the inverse
\(C=\left[\begin{array}{ccc}-1 & 0 & 1 \\ 1 & 1 & 3 \\ 2 & 0 & 2\end{array}\right]\), then \(A^{-1}\) equals

78968 If \(A=\left[\begin{array}{ll}2 & -3 \\ 5 & -7\end{array}\right]\), then \(A+A^{-1}=\)

78969 If \(A^{2}-A+I=0\), then the inverse of \(A\) is

78970 If \(A=\left[\begin{array}{ccc}2 & 3 & -5 \\ 1 & 4 & 9 \\ 0 & 7 & -2\end{array}\right]\), then apply \(C_{3} \rightarrow C_{3}+3 C_{2}\) to form a matrix \(B=\left[b_{i j}\right]\) and then find the value of \(a_{22}+b_{21}\) and \(a_{11} b_{11}+a_{22} b_{22}\) respectively.

78971 If \(\mathbf{A}=\left[\begin{array}{ccc}\sec \theta & \tan \theta & \mathbf{0} \\ \boldsymbol{\operatorname { t a n }} \theta & \boldsymbol{\operatorname { s e c }} \theta & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{1}\end{array}\right]\), then

78967 If the product of the matrix \(B=\)
\(\left[\begin{array}{ccc}2 & 6 & 4 \\ 1 & 0 & 1 \\ -1 & 1 & -1\end{array}\right]\) with a matrix \(A\) has the inverse
\(C=\left[\begin{array}{ccc}-1 & 0 & 1 \\ 1 & 1 & 3 \\ 2 & 0 & 2\end{array}\right]\), then \(A^{-1}\) equals

78968 If \(A=\left[\begin{array}{ll}2 & -3 \\ 5 & -7\end{array}\right]\), then \(A+A^{-1}=\)

78969 If \(A^{2}-A+I=0\), then the inverse of \(A\) is

78970 If \(A=\left[\begin{array}{ccc}2 & 3 & -5 \\ 1 & 4 & 9 \\ 0 & 7 & -2\end{array}\right]\), then apply \(C_{3} \rightarrow C_{3}+3 C_{2}\) to form a matrix \(B=\left[b_{i j}\right]\) and then find the value of \(a_{22}+b_{21}\) and \(a_{11} b_{11}+a_{22} b_{22}\) respectively.

78971 If \(\mathbf{A}=\left[\begin{array}{ccc}\sec \theta & \tan \theta & \mathbf{0} \\ \boldsymbol{\operatorname { t a n }} \theta & \boldsymbol{\operatorname { s e c }} \theta & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{1}\end{array}\right]\), then

78967 If the product of the matrix \(B=\)
\(\left[\begin{array}{ccc}2 & 6 & 4 \\ 1 & 0 & 1 \\ -1 & 1 & -1\end{array}\right]\) with a matrix \(A\) has the inverse
\(C=\left[\begin{array}{ccc}-1 & 0 & 1 \\ 1 & 1 & 3 \\ 2 & 0 & 2\end{array}\right]\), then \(A^{-1}\) equals

78968 If \(A=\left[\begin{array}{ll}2 & -3 \\ 5 & -7\end{array}\right]\), then \(A+A^{-1}=\)

78969 If \(A^{2}-A+I=0\), then the inverse of \(A\) is

78970 If \(A=\left[\begin{array}{ccc}2 & 3 & -5 \\ 1 & 4 & 9 \\ 0 & 7 & -2\end{array}\right]\), then apply \(C_{3} \rightarrow C_{3}+3 C_{2}\) to form a matrix \(B=\left[b_{i j}\right]\) and then find the value of \(a_{22}+b_{21}\) and \(a_{11} b_{11}+a_{22} b_{22}\) respectively.

78971 If \(\mathbf{A}=\left[\begin{array}{ccc}\sec \theta & \tan \theta & \mathbf{0} \\ \boldsymbol{\operatorname { t a n }} \theta & \boldsymbol{\operatorname { s e c }} \theta & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{1}\end{array}\right]\), then

78967 If the product of the matrix \(B=\)
\(\left[\begin{array}{ccc}2 & 6 & 4 \\ 1 & 0 & 1 \\ -1 & 1 & -1\end{array}\right]\) with a matrix \(A\) has the inverse
\(C=\left[\begin{array}{ccc}-1 & 0 & 1 \\ 1 & 1 & 3 \\ 2 & 0 & 2\end{array}\right]\), then \(A^{-1}\) equals

78968 If \(A=\left[\begin{array}{ll}2 & -3 \\ 5 & -7\end{array}\right]\), then \(A+A^{-1}=\)

78969 If \(A^{2}-A+I=0\), then the inverse of \(A\) is

78970 If \(A=\left[\begin{array}{ccc}2 & 3 & -5 \\ 1 & 4 & 9 \\ 0 & 7 & -2\end{array}\right]\), then apply \(C_{3} \rightarrow C_{3}+3 C_{2}\) to form a matrix \(B=\left[b_{i j}\right]\) and then find the value of \(a_{22}+b_{21}\) and \(a_{11} b_{11}+a_{22} b_{22}\) respectively.

78971 If \(\mathbf{A}=\left[\begin{array}{ccc}\sec \theta & \tan \theta & \mathbf{0} \\ \boldsymbol{\operatorname { t a n }} \theta & \boldsymbol{\operatorname { s e c }} \theta & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{1}\end{array}\right]\), then